Around 120,000 passengers have had their flights cancelled during the chaos
London's Gatwick Airport reopened on Friday for a limited number of flights, after mysterious drone sightings caused chaos that left tens of thousands of passengers stranded over the past three days.
Police said they were still hunting for the drone operator or operators and Transport Secretary Chris Grayling said "military capabilities" were being deployed to safeguard the airport.
"Gatwick's runway is currently available and a limited number of aircraft are scheduled for departure and arrival," the airport said on Twitter. It advised passengers to check the status of their flights before travelling to the airport.
Over 30 flights had either landed or taken off by 8:15am (0815 GMT), with around 700 departures expected throughout the day, according to the airport's chief operating officer Chris Woodroofe.
But he told BBC Radio 4's Today programme that police have still yet to find the operator of the drones and Gatwick was only able to reopen due to the "additional mitigating measures" provided by government agencies and the military.
The army was called in on Thursday to offer additional support with the defence ministry deploying specialist equipment.
"There are a range of measures which are there today which should give passengers confidence that they are safe to fly," Grayling told the BBC.
He said "military capabilities" were being deployed, without giving further details.
Government officials held an emergency meeting on Friday to discuss the situation.
There have been more than 50 sightings of the device or devices since 9pm (2100 GMT) on Wednesday and shooting down the drone is now an option, Jason Tingley of Sussex Police earlier told reporters.
"We will do what we can to take that drone out of the sky and remove that disruption so we can get Gatwick back to normal," he said.
"One of the options is to use firearms officers if that presents itself -- they have been out on the ground today (Thursday) and that's a consideration and a tactical option that's open to us."
Justin Burtenshaw, head of armed policing for Sussex and Surrey said on Thursday: "Each time we believe we get close to the operator, the drone disappears. When we look to reopen the airfield the drone reappears."
British Airways confirmed on Twitter on Friday that it had received confirmation "advising the airport is back open and the majority of flights operating as scheduled."
Around 120,000 passengers have had their flights cancelled during the chaos.
The story dominated Britain's newspapers on Friday.
Popular tabloid The Sun splashed "The Drone Wolf" across its front-page, speculating that the culprit was an eco-activist.
The Daily Telegraph also reported that authorities suspected an environmental protest, according to civil service sources.
Gisele Fenech, 43, who was travelling to Malta, was among those stranded at the airport.
"We're meeting family and it's my daughter's birthday today so it's gone all wrong. We've been looking forward to this for so long," she told AFP.
"Everyone's trying to get home for Christmas."
Gatwick, around 30 miles (50km) south of the British capital, is the eighth-busiest airport in Europe and sits behind Mumbai as the world's busiest single runway air hub.
Inbound flights were diverted to other airports, including Paris, while passengers waiting to take off faced gruelling delays as airlines cut services.
Some 10,000 passengers were affected on Wednesday night, and a further 110,000 who had been due to either take off or land at the airport on 760 flights Thursday.
Musab Rashid, 22, who was going to Copenhagen, said: "It's wrong, it's childish of them to do this, because it's affected more than 100,000 people."
Two drones were first spotted flying over Gatwick at around 9pm (2100 GMT) on Wednesday. The airfield briefly reopened at 3am on Thursday, but had to be closed again following further sightings through the day.
British Prime Minister Theresa May said she sympathised with passengers and vowed action.
"We will continue to work with the Gatwick authorities and police will be working... in order to bring this to a close," she told a press conference in London.
Under a new British law, drones cannot be flown near aircraft or within a kilometre of an airport, or at an altitude of over 400 feet (122 metres).
May warned the perpetrators they could face up to five years in prison for endangering an aircraft under recently passed legislation.